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1.
1983年总目录     
昆虫的卵····,·························……夏邦颖动物界的一个新门—扁盘动物门简介…… ......·.··..························……吴宝铃海参的形态结构和生活习性······……许慈荣娱蛤和马陆···············……张崇洲张福祥略淡软体动物的齿舌·····一陈德牛高家祥弓l‘植物学部分,矛2,哎少.12,J,‘6 6 60曰,8,1 04︸6曰,3廿0 93润翻,.﹄12,‘,勺,‘22,‘,几22,且.几,几,‘,‘,j,jJ,4︼,︼勺巴」 作者世界著名观赏树种—琪碉······……林…  相似文献   

2.
胡杨异形叶叶绿素荧光特性对高温的响应   总被引:4,自引:0,他引:4  
王海珍  韩路  徐雅丽  王琳  贾文锁 《生态学报》2011,31(9):2444-2453
胡杨(Populus euphratica Oliv)是塔里木极端干旱荒漠区优势乔木树种,由于其生长在荒漠环境中,极端高温远高于其它地区,因此研究胡杨对高温胁迫的响应特征对于解释胡杨的抗逆机理与生态适应策略具有极为重要的意义。以胡杨3种典型的异形叶为材料,研究不同温度对其叶绿素荧光特性和能量分配的影响。结果表明,25-45 ℃温度下胡杨异形叶的F0FmFv/FmFv/F0变化不大,尤其Fv/Fm仍能保持在0.78左右,光合反应正常;高温胁迫下(>45 ℃)FmFv/F0Fv/FmF'v/F'mqPΦPSⅡ、P和ETR均大幅降低;F0qNE显著上升,而D先上升后下降,说明高温抑制了PSⅡ的功能,使PSⅡ反应中心活性下降,QA-的还原速率加快,光化学电子传递速率降低,某些能量耗散途径受阻,影响了PSⅠ和PSⅡ激发能的平衡分配,最终导致光合机构受损、光合速率降低。胡杨3种异形叶的叶绿素荧光参数随温度升高变幅不同,高温处理下锯齿阔卵形叶各参数均高于卵形叶与条形叶,表明锯齿阔卵形叶比卵形叶和条形叶具有更强的高温耐受能力。用模糊数学的隶属度函数对胡杨3种异形叶的耐热性进行综合评价,锯齿阔卵形叶的耐热性最强。  相似文献   

3.
We studied the peculiarities of permeability with respect to the main extracellular cations, Na+ and Ca2+, of cloned low-threshold calcium channels (LTCCs) of three subtypes, Cav3.1 (α1G), Cav3.2 (α 1H), and Cav3.3 (α1I), functionally expressed in Xenopus oocytes. In a calcium-free solution containing 100 mM Na+ and 5 mM calcium-chelating EGTA buffer (to eliminate residual concentrations of Ca2+) we observed considerable integral currents possessing the kinetics of inactivation typical of LTCCs and characterized by reversion potentials of −10 ± 1, −12 ± 1, and −18 ± 2 mV, respectively, for Cav3.1, Cav3.2, and Cav3.3 channels. The presence of Ca2+ in the extracellular solution exerted an ambiguous effect on the examined currents. On the one hand, Ca2+ effectively blocked the current of monovalent cations through cloned LTCCs (K d = 2, 10, and 18 μM for currents through channels Cav3.1, Cav3.2, and Cav3.3, respectively). On the other hand, at the concentration of 1 to 100 mM, Ca2+ itself functioned as a carrier of the inward current. Despite the fact that the calcium current reached the level of saturation in the presence of 5 mM Ca2+ in the external solution, extracellular Na+ influenced the permeability of these channels even in the presence of 10 mM Ca2+. The Cav3.3 channels were more permeable with respect to Na+ (P Ca/P Na ∼ 21) than Cav3.1 and Cav3.2 (P Ca/P Na ∼ 66). As a whole, our data indicate that cloned LTCCs form multi-ion Ca2+-selective pores, as these ions possess a high affinity for certain binding sites. Monovalent cations present together with Ca2+ in the external solution modulate the calcium permeability of these channels. Among the above-mentioned subtypes, Cav3.3 channels show the minimum selectivity with respect to Ca2+ and are most permeable for monovalent cations. Neirofiziologiya/Neurophysiology, Vol. 38, No. 3, pp. 183–192, May–June, 2006.  相似文献   

4.
Trypanosomes were isolated from Atlantic cod Gadus morhua L. collected from several fjords in western Norway. Morphological studies showed that the 12 infections studied represented a single species, identified as Trypanosoma pleuronectidium Robertson, 1906 which is resurrected and redescribed. This species is characterised by its body length (57.9 ± 5.4 μm), nearly central nucleus (NI = 1.05 ± 0.12) and relatively short post-kinetoplastic (PK) region (3.2 ± 0.8 μm). T. pleuronectidium is transmitted by the leech Calliobdella nodulifera (Malm). T. murmanense Nikitin, 1927 (emend.) is delimited to a species transmitted by the leech Johanssonia arctica (Johansson). This species is separated from T. pleuronectidium by its attained body length, more anterior nucleus, presence of cytoplasmic refractive granules, adnuclear vacuoles and by a longer PK region. Partial SSU rDNA sequences of T. pleuronectidium and T. murmanense from Norway (1980 nt) diverged by 1.9%. The nominal North Atlantic and Mediterranean trypanosome species are reviewed, and T. flesi Lebailly, 1904, T. bothi Lebailly, 1905 and T. limandae Brumpt & Lebailly, 1904 are considered synonyms of T. platessae Lebailly, 1904. T. triglae senegalensis Ranque, 1973 is not considered conspecific with T. triglae Neumann, 1909, and consequently raised to species status as T. senegalense Ranque, 1973. Some other likely synonymies are discussed. In addition to T. pleuronectidium and T. murmanense, the following marine teleost trypanosomes are provisionally listed as valid species pending further study: T. callionymi Brumpt & Lebailly, 1904; T. cotti Brumpt & Lebailly, 1904; T. delagei Brumpt & Lebailly, 1904; T. dorhni Yakimov, 1911; T. gobii Brumpt & Lebailly, 1904; T. laternae Lebailly, 1904; T. myoxocephali Fantham, Porter & Richardson, 1942; T. platessae Lebailly, 1904; T. scorpaenae Neumann, 1909; T. soleae Laveran & Mesnil, 1901; T. triglae Neumann, 1909; and T. yakimovi Yakimov, 1911.  相似文献   

5.
《生物技术通讯》2003,14(6):582-586
(第14卷,总第55~60期)研究报告 遗传修饰小鼠胚胎干细胞种系嵌合体小鼠的研制·································……程董,周江,谭晓红,等(l) 新型纳米转染试剂转染PNP自杀基因体外杀伤实验···························……杜芝燕,黄伟,李峰生,等(4) 犬2型腺病毒E3区表达载体的构建················································……邱薇,夏咸柱,范泉水,等(8) 间隔臂和探针长度与寡核昔酸芯片重复性相关性研究····…  相似文献   

6.
Annual gross primary productivity in mesotrophic Shahidullah Hall pond (Dhaka, Bangladesh) was 1383.35 g C m−2 y−1 (arithmetic mean). Daily primary productivity (between 1.6 and 6.8 g C m−2 d−1 was correlated with chlorophylla, day length and dissolved silica. Chlorophylla related significantly withk, incident light, SRP, alkalinity and conductivity. A negative correlation existed between biomass and rainfall. Productivity, biomass, conductivity, alkalinity, and SRP increased after mid-winter.k, I k andZ eu varied according seasonally.P max related directly with temperature. Seasonal variation of ∝ B was 0.0049–0.0258 mg C (mg chla mmol PAR)−1 m−2. Q10 was 2.12, community respiration 1334.99 g C m−2 y−1, and the underwater light climate 186.43μE m−2 s−1.  相似文献   

7.
千烟洲红壤丘陵区人工针叶林土壤CH4排放通量   总被引:3,自引:0,他引:3       下载免费PDF全文
 CH4在温室效应中起着重要作用,为估算中亚热带CH4的源汇现状,评价森林生态系统对温室效应的影响,采用静态箱-气相色谱法研究了千烟洲红壤丘陵区人工针叶林的土壤CH4 排放通量特征及水热因子对其的影响。对2004年9月~2005年12月期间的观测结果分析表明 :千烟洲人工针叶林土壤总体表现为大气CH4的吸收汇,原状林地土壤(Forest soil)情况下,CH4通量的变化为7.67~-67.17μg&;#8226;m-2&;#8226;h-1,平均为-15.53μg&;#8226;m-2&;#8226;h-1;无凋落物处理(Litter-free)情况下,CH4通量的变化是9.31~-90.36 μg&;#8226;m-2&;#8226;h-1,平均为-16.53μg&;#8226;m-2&;#8226;h-1。 二者对土壤CH4的吸收表现出明显的季节变化规律,秋>夏>冬>春,但无凋落物处理CH4变化幅度较原状林地土壤大,无凋落物处理吸收高峰出现在10月,最低值出现在翌年3月,原状林地土壤则分别在9月和翌年2月,均提前1个月。对土壤CH4吸收通量与温度和湿度的相关分析表明: 无论是原状林地土壤还是无凋落物处理情况下,土壤CH4通量都与地下5 cm的温度和湿度相关性最高。偏相关分析反映了不同季节水热配置对土壤吸收CH4通量的影响:冬季为12月~翌年2月,温度起主要作用;雨季3~6月,温度作用为主,随着温度的升高而升高,水分作用微弱;7~8月,CH4吸收通量随着湿度的降低而增加,但高温限制了CH4的吸收;秋季(9~11月)水热配置适宜,CH4通量达到高峰值。总之,CH4吸收通量随着温度的升高和 湿度的降低而增大,但温度过高会抑制其吸收。  相似文献   

8.
三画于龙川,韩济生:家兔下丘脑弓状核区参与从伏核到中脑导水管周围灰质的下行镇痛通路,·····”·“········一(1 17)马新亮,减益民,朱妙章,王跃民:肾上腺髓质在急性心肌缺血时血液流变学变化中的作用····一”···……(1 40)马新亮,范家骏,朱妙章,减益民:急性心肌缺血时低切变率下全血粘度变化机理研究·····“··“”······……(289)四西尹丽艳,谢选珠,高晓明,夏振勤,谢翠微,汤健:心钠素在强啡肤降压效应中的作用··········”······……(343)王庆(见李慧麟等)·····“·”·”····…  相似文献   

9.
内蒙古不同类型草地叶面积指数遥感估算   总被引:5,自引:0,他引:5  
叶面积指数(Leaf Area Index,LAI)是重要的植被结构参数,反演LAI是植被遥感的重要研究内容之一。根据在内蒙古呼伦贝尔和锡林浩特草原利用LAI 2000观测的草地LAI,比较了不同植被指数(SR、RSR、EVI、NDVI、SAVIARVI)估算不同类型草地LAI的能力,建立了基于Landsat-5 TM遥感数据的LAI估算模型,并利用LAI观测数据对模型进行了检验,生成了研究区内草地LAI分布图,据此对MODIS LAI产品一致性进行了评价。结果表明,在呼伦贝尔和锡林浩特两个研究区,RSRLAI的相关性最高(R2分别为0.628、0.728,RMSE分别为0.512、0.490),在低密度草地,RSR的优势更为明显;验证表明,根据RSR建立的LAI估算模型的精度可达70%;利用TM数据生成的两个地区的LAI(TM LAI)空间变化明显,锡林浩特草地的LAI值整体上低于呼伦贝尔草地;在呼伦贝尔和锡林浩特,MODIS LAI产品与TM LAI一致性分别为0.566,0.323,MODIS LAI产品高估了呼伦贝尔草地LAI值,而在锡林浩特研究区则存在低估现象。  相似文献   

10.
第1期研究报告假单胞菌XN一1硝基苯降解性质粒的提取及研究························……刘春,周集体,黄丽萍,吕红(1)嗅氨酸降解菌株的分离和特性···································……李莹,蔡宝立,庄源益,丁春丽,杨湘龙(5)富硒姬松茸液体培养条件的研究··,·····························,·····················……杨淑云,刘朝贵,朱凯(9)缺失氨肤酶N的变铅青链霉菌的构建和鉴定········……,’’,,····…  相似文献   

11.
Citrus volkameriana (L.) plants were grown for 43 d in nutrient solutions containing 0, 2, 14, 98, or 686 μM Mn (Mn0, Mn2, Mn14, Mn98, and Mn686, respectively). To adequately investigate the combined effects of Mn nutrition and irradiance on photosystem 2 (PS2) activity, irradiance response curves for electron transport rate (ETR), nonphotochemical quenching (qN), photochemical quenching (qP), and real photochemical efficiency of PS2 (ΦPS2) were recorded under 10 different irradiances (66, 96, 136, 226, 336, 536, 811, 1 211, 1 911, and 3 111 μmol m−2 s−1, I66 to I3111, respectively) generated with the PAM-2000 fluorometer. Leaf chlorophyll content was significantly lower under Mn excess (Mn686) compared to Mn0; its highest values were recorded in the treatments Mn2-Mn98. However, ETR and ΦPS2 values were significantly lower under Mn0 compared to the other Mn treatments, when plants were exposed to irradiances ≥96 μmol m−2 s−1. Furthermore, Mn0 plants had significantly higher values of qN and lower values of qP at irradiances ≤226 and ≥336 μmol m−2 s−1, respectively, than those grown under Mn2-Mn686. Irrespective of Mn treatment, the values of ΦPS2 and qN decreased, while those of qP increased progressively by increasing irradiance from I136 to I3111. Finally, Mn2-Mn98 plants were less sensitive to photoinhibition of photosynthesis (≥811 μmol m−2 s−1) than the Mn686 (≥536 μmol m−2 s−1) and Mn0 (≥336 μmol m−2 s−1) ones.  相似文献   

12.
Yang J Y  Wang C K 《农业工程》2006,26(6):1640-1646
Quantifying soil respiration components and their relations to environmental controls are essential to estimate both local and regional carbon (C) budgets of forest ecosystems. In this study, we used the trenching-plot and infrared gas exchange analyzer approaches to determine heterotrophic (RH) and autotrophic respiration (RA) in the soil surface CO2 flux for six major temperate forest ecosystems in northeastern China. The ecosystems were: Mongolian oak forest (dominated by Quercus mongolica), aspen-birch forest (dominated by Populous davidiana and Betula platyphylla), mixed wood forest (composed of P. davidiana, B. platyphylla, Fraxinus mandshurica, Tilia amurensis, Acer amono, etc.), hardwood forest (dominated by F. mandshurica, Juglans mandshurica, and Phellodendron amurense), Korean pine (Pinus koraiensis), and Dahurian larch (Larix gmelinii) plantations, representing the typical secondary forest ecosystems in this region. Our specific objectives were to: (1) quantify RH and its relationship with the environmental factors of the forest ecosystems, (2) characterize seasonal dynamics in the contribution of root respiration to total soil surface CO2 flux (RC), and (3) compare annual CO2 fluxes from RH and RA among the six forest ecosystems. Soil temperature, water content, and their interactions significantly affected RH in the ecosystems and accounted for 46.5%–78.8% variations in RH. However, the environmental controlling factors of RH varied with ecosystem types: soil temperature in hardwood and Dahurian larch forest ecosystems, soil temperature, and water content in the others. The RC for hardwood, poplar-birch, mixed wood, Mongolian oak, Korean pine, and Dahurian larch forest ecosystems varied between 32.40%–51.44%, 39.72%–46.65%, 17.94%–47.74%, 34.31%–37.36%, 33.78%–37.02%, and 14.39%–35.75%, respectively. The annual CO2 fluxes from RH were significantly greater than those from RA for all the ecosystems, ranging from 337–540 g Cm-2a-1 and 88‐331 gCm-2a-1 for RH and RA, respectively. The annual CO2 fluxes from RH and RA differed significantly among the six forest ecosystems.  相似文献   

13.
在深圳市内伶仃岛薇甘菊危害的不同群落生境中,设立9块样地81个小样方,用森草净(即70%嘧碘降水溶性粉剂)杀灭样地中的薇甘菊施量为0.0001~0.02 g•m-2,结果表明:各浓度的森草净杀灭效果均较好,杀灭率随着用药量的增加而提高;在坡地和溪谷生境中,森草净用药量分别为0.05~0.1 g•m-2、>0.2 g•m-2能较彻底地杀灭薇甘菊。应用HPLC法检测样地土壤中嘧磺隆残留量,溪谷土壤中嘧磺隆半衰期C=C0•e-0.083TT1/2=8.4,施药后37 d消解95.9%,坡地高浓度级半衰期C=C0•e-0.046TT1/2=15.1 d,施药后37 d消解85.0%,坡地低浓度级半衰期C=C0•e-0.090T, T1/2=7.7 d,施药后15 d消解742%。不同浓度森草净处理样地,施药后7、15、37 d均可检测到嘧磺隆,并且含量越来越小,但施药后68 d的土样,均未检测到嘧磺隆的存在。  相似文献   

14.
Phenyl, p-tolyl, and p-tert-butylphenyl β-1-thio-N-acetylglucosaminides were synthesized by the treatment of thiophenols with peracetate of α-D-glucosaminyl chloride in the presence of triethylamine or under the conditions of phase-transfer catalysis with quaternary ammonium salts. The compounds synthesized were used for obtaining of glycosides of 4,6-O-isopropylidene-N-acetylmuramic acid, which were coupled with L-Ala-D-Glu(NH2)-OBzl and then deprotected to obtain the target aryl β-thioglycosides of N-acetylmuramyl-L-analyl-D-isoglutamine (MDP). The aryl β-thioglycosides of MDP were found to stimulate an antibacterial resistance toward Staphylococcus aureus in mice. The reliable induction of the spontaneous activity of natural killers in the population of blood mononuclear cells was observed only for phenyl β-thio-MDP at a dose of 200 μg/ml. Original Russian Text ? A.E. Zemlyakov, V.N. Tsikalova, L.R. Azizova, V.Ya. Chirva, E.L. Mulik, M.V. Shkalev, O.V. Kalyuzhin, M.V. Kiselevsky, 2008, published in Bioorganicheskaya Khimiya, 2008, Vol. 34, No. 2, pp. 245–251.  相似文献   

15.
CH4在温室效应中起着重要作用,为估算中亚热带CH4的源汇现状,评价森林生态系统对温室效应的影响,采用静态箱-气相色谱法研究了千烟洲红壤丘陵区人工针叶林的土壤CH4 排放通量特征及水热因子对其的影响。对2004年9月~2005年12月期间的观测结果分析表明 :千烟洲人工针叶林土壤总体表现为大气CH4的吸收汇,原状林地土壤(Forest soil)情况下,CH4通量的变化为7.67~-67.17μg•m-2•h-1,平均为-15.53μg•m-2•h-1;无凋落物处理(Litter-free)情况下,CH4通量的变化是9.31~-90.36 μg•m-2•h-1,平均为-16.53μg•m-2•h-1。 二者对土壤CH4的吸收表现出明显的季节变化规律,秋>夏>冬>春,但无凋落物处理CH4变化幅度较原状林地土壤大,无凋落物处理吸收高峰出现在10月,最低值出现在翌年3月,原状林地土壤则分别在9月和翌年2月,均提前1个月。对土壤CH4吸收通量与温度和湿度的相关分析表明: 无论是原状林地土壤还是无凋落物处理情况下,土壤CH4通量都与地下5 cm的温度和湿度相关性最高。偏相关分析反映了不同季节水热配置对土壤吸收CH4通量的影响:冬季为12月~翌年2月,温度起主要作用;雨季3~6月,温度作用为主,随着温度的升高而升高,水分作用微弱;7~8月,CH4吸收通量随着湿度的降低而增加,但高温限制了CH4的吸收;秋季(9~11月)水热配置适宜,CH4通量达到高峰值。总之,CH4吸收通量随着温度的升高和 湿度的降低而增大,但温度过高会抑制其吸收。  相似文献   

16.
植物MADS-box基因家族编码高度保守的转录因子,参与了包括花器官发育和开花在内的多种发育进程。为阐释兰科植物成花的分子调控机制,根据MADS-box基因保守序列设计简并引物,用RACE方法从朵丽蝶兰花葶中克隆到1个MADS-box家族基因,该基因cDNA全长960 bp,包含37 bp 5′UTR,一个738 bp的开放阅读框(ORF)和185 bp 3′UTR,共编码245个氨基酸。序列和系统进化树分析表明,该基因与其他植物的MADS-box基因具有很高的同源性,属于AP1/FUL-like亚家族,命名为DtpsMADS1,GeneBank登录号为JQ065097。实时荧光定量PCR检测结果显示:DtpsMADS1具有明显的组织表达特异性;在根和叶中,DtpsMADS1在花前期和花后期表达量较高;苗期和盛花期表达量较低;DtpsMADS1在花葶中的表达趋势与根和叶相似;而在花器官中,DtpsMADS1只有痕量表达。由此推断,DtpsMADS1可能参与开花进程调控,而不参与花器官的形态建成。  相似文献   

17.
光敏色素互作因子(PIFs)是光信号响应的关键负调控因子,其中PIF4作为该家族核心成员在响应外界光温变化,整合多种激素合成和信号转导中起着关键性作用。为了明确大豆GmPIF4s [phytochrome interaction factor 4s of Glycine max (L.) Merr.] 的功能和编码基因对荫蔽诱导的表达响应,该研究以耐荫性大豆‘南豆25’(ND25)和不耐荫性大豆‘荣县冬豆’(RD)为材料,通过生物信息学和分子生物学等方法,比较分析了豆科植物PIF4s的生物信息学特点,并采用qRT PCR方法分析大豆不同组织(根、茎、叶、茎尖分生组织)、全光照和12 h/12 h光周期下不同荫蔽时间诱导叶片GmPIF4s及其不同耐荫性大豆材料间GmPIF4s的表达特征,为培育高产、耐荫的大豆品种提供理论依据。 结果表明:(1)在豆科植物中鉴定到53个同源PIF4s,其中大豆包含7个同源GmPIF4s,长度介于296~562氨基酸之间,分子量范围为41 491.9~62 228.39 Da,所有GmPIF4s均包含有bHLH结构域,无跨膜结构,为亲水性蛋白且定位于细胞核中;蛋白二级及三级结构预测显示,GmPIF4a、GmPIF4b与拟南芥AtPIF4结构最为相似。(2)qRT PCR分析表明,GmPIF4s基因表达具有组织特异性;在耐荫性大豆品种ND25中,GmPIF4aGmPIF4bGmPIF4d相对表达量在根、叶、茎和茎尖分生组织中表达最高,除GmPIF4aGmPIF4eGmPIF4f外,其余GmPIF4s在地上部各组织中表达量均相对较高;不耐荫性大豆品种RD中, GmPIF4aGmPIF4bGmPIF4cGmPIF4d在叶中相对表量较高,除GmPIF4fGmPIF4g外,其余GmPIF4s在地上部各组织中表达量均相对较高。(3)全光照下荫蔽处理时间延长,大豆GmPIF4aGmPIF4bGmPIF4cGmPIF4d基因均受荫蔽的强烈诱导,表达量显著上调;12 h/12 h光周期条件下无论是正常光还是荫蔽条件下,随着处理时间的延长,白天GmPIF4s表达量呈现下调趋势,夜晚却呈现上调表达趋势,推测GmPIF4s受昼夜节律调控。(4)荫蔽条件下GmPIF4s在不同耐荫性大豆的表达显示,随着荫蔽时间的延长,耐荫性大豆品种ND25与不耐荫性大豆品种RD的GmPIF4aGmPIF4bGmPIF4cGmPIF4d均上调表达,但在不耐荫性大豆品种RD中表达量相对更高,并于荫蔽处理8 h后两材料的GmPIF4s表达差异达到极显著水平。  相似文献   

18.
植物蒸腾导度是表征土壤-植物-大气连续体(SPAC)中植物-大气间水汽传导过程、反映植物水分调控能力的一类重要变量,常见有冠层导度(Gc)、冠层气孔导度(Gs)与叶片气孔导度(gs),明确三者在反映冠层蒸腾过程时的异同或关联性对于理解植物水分利用机制具有重要意义。本研究基于对黄土高原果园苹果树生长季内树干液流(Js)及环境因子的连续观测,计算了GcGs及脱耦联系数(Ω)等变量,并与短期连续观测的叶片气孔导度(gs)比较,分析了GcGsgs在反映冠层蒸腾特征方面的异同及其关系。结果表明,日变化过程中Gsgs呈"单峰"型曲线,而Gc则呈"先增后减,午后抬升"的"双峰"型曲线。gsGs存在较紧密的线性关系(R2=0.80),但与Gc的线性关系较弱(R2=0.02)。GcGs均随大气水汽压亏缺(VPD)的变化呈现确定的规律,其中,上边界函数呈递减的对数函数关系,平均值则符合先增后减的Log-Normal函数关系(R2>0.95),拐点对应的VPD值分别为1.33和1.16 kPa。在一日内,Gs对VPD变化的响应过程与gs对VPDL (基于叶片温度计算的水汽压亏缺)变化的响应过程总体一致,其一致性高于Gc对VPD变化的响应。整个生长季(4-10月)中果树的Ω平均值为0.12,随着Ω递减,GcGs的线性相关性愈趋紧密,其斜率呈递增趋势,Gc越来越趋近于Gs。研究结果表明,在北方地区,基于树干液流的监测能较准确的推导整株并估算林分的冠层蒸腾导度。与实测gs的变化过程比较,GsGc具有更高的一致性,Gs可以作为描述苹果树水分利用过程响应大气驱动的更为恰当的变量。  相似文献   

19.
南极长城站地区土壤微生物生态作用的初步探讨   总被引:4,自引:0,他引:4  
从南极长城站附近联合采样13个,并进行了土壤微生物的数量统计与种类鉴定。氨化细菌的菌量为104~106cells/g,共7个属:微球菌属(Micrococcus),葡萄球菌属(Staphylococcus),假单胞菌属(Pseudomonas),芽孢杆菌属(Bacillus),产碱菌属(Alcaligenes),黄杆菌属(Flavobacterium),节杆菌属(Arthrobacter);固氮细菌菌量为105~107cells/g,仅一个固氮菌属(Azotobacter);硝化细菌一般为104cells/g,分属两个属:硝化杆菌属(Nitrobacter),硝化球菌属(Nitrococcus);真菌为103cells/g,分属5个属:青霉菌属(Penicillium),金孢霉菌属(Chrysosporium),枝孢霉菌属(Cladosporium),曲霉菌属(As-pergillus),散囊菌属(Eurotium),反硝化菌为 102~104cells/g,分属 3个属:假单胞菌属(Pseudomonas),微球菌属(Micrococcus),芽孢杆菌属(Bacillus);放线菌分属3个属:链霉菌属(Streptomyces),小单孢菌属(Micromonospora),和诺卡氏菌属(Nocardia)。联采样品12℃培养的出现率主要类群是:假单胞菌属(42%),芽孢杆菌属(35%),微球菌属(31%),节杆菌属(27%),青霉菌属(58%),枝孢霉菌属(54%),硝化杆菌属(81%),固氮菌属(88%),反硝化细菌中主要是假单胞菌属(58%),芽孢杆菌属(38%)。文中还讨论了微生物菌量与土壤总碳、总氮的相关性及其在该地区氮循环中的生态学作用。  相似文献   

20.
邻二氮菲-Fe2+氧化法检测H2O2/Fe2+产生的羟自由基   总被引:122,自引:0,他引:122  
报告检测H2O2/Fe2+所产生羟自由基的新方法. 羟自由基氧化反应后, 邻二氮菲-Fe2+的A536明显下降, 且△A536与邻二氮菲, FeSO4及H2O2呈量效关系, 随反应时间延长, △A536依幂函数规律上升. 此法试验结果表明, 甘露醇, 抗坏血酸及硫肥清除羟自由基作用呈明显的量效关系.  相似文献   

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